Recently at least one model of the Cadillac automobile manufactured by General Motors has been available with a theft deterrent alarm system. When activated or armed anyone unlocking the automobile from the outside, for example, through an open window, causes the horn to blast intermittently and the headlamps to flash on and off. A starter disablement circuit associated therewith, thereafter prevents the automobile engine from being started by its conventional ignition key. The Cadillac system can be inactivated by unlocking the vehicle outside door lock. Although I do not fully understand the details of the Cadillac alarm circuit, I believe the system would become inoperative if a wire to the door lock was cut or removed.
In my prior U.S. Pat. Nos. 2,519,758; 2,520,363; 2,521,516; 2,766,343; 3,263,211; 3,372,373; 3,372,374 and 4,575,706; and 4,354,174 and my pending U.S. patent application having Ser. No. 387,457, filed June 11, 1982, now U.S. Pat. No. 4,638,296 and U.S. Pat. No. 4,480,249 issued Oct. 30, 1984, I have disclosed combined ignition and starter switches, circuits and locks, as well as an operated flashing hazard light and horn circuits which are adopted to be incorporated into the electrical systems of existing automotive vehicles with readily available and inexpensive components.